Minden (ship, 1882)
The Minden is a bucket-chain steam dredger that has been a museum ship at the Museum of German Inland Shipping in Duisburg-Ruhrort since 1982, together with the side-wheel steam tug Oscar Huber .
history
The Minden was built in Mainz in 1882 . The dredger , which until 1979 for dredging on the Weser between Stolzenau and Hameln was used belonged to the Water and Shipping Authority Minden of the Waterways and Shipping Directorate center in Hannover .
The Minden was one of several steam dredgers on the Weser, also known are the Hameln , built in 1878, and the Hoya , built in the same year, each of which dredged the fairway on a specific section of the Weser. The steam drive proved to be particularly beneficial for the hard slate clay of the Weser bottom. If the buckets got stuck, the machine would come to a standstill, because reversing would not harm it. With a renewed burst of force, the excavator "went down on its knees" and the chunk broke loose. The dredged material fell from the buckets into chutes or onto a conveyor belt, also driven by the steam engine, and from there into a boat alongside.
Since the Minden excavator did not have its own drive engine, it does not belong to the “ship” category, but is a “floating device”.
The facility below deck was intended for a crew of four who would also live on board during the mission. The crew was accommodated in three rooms: the excavator or equipment operator and the machinist in one room each in the bow, two deckmen in one room in the stern. There was also a kitchen as well as a bathroom and toilet on board.
Parts of the furnishings date from the construction time of the excavator (bedroom furniture, kitchen stove). However, in the 1950s, the furniture was supplemented by a few fixtures and fittings that were supposed to make life on board easier for the crew (shower, oil stoves, refrigerator and the cladding of the walls). Since most of the smaller repairs, for example to the chains, had to be done immediately, one of the prerequisites for becoming an excavator or equipment operator was training as a boatman or craftsman, preferably from a metal subject. A total of seven excavator operators directed the work on board the excavator during the 97 years of its use.
technology
Boiler and machine
The steam engine of Minden never had to be replaced, the boiler against it three times. The first boiler from 1882 only produced 6 Atü , but had to be replaced in 1911 because it could no longer be operated due to a crack. The now built-in boiler already performed like the current 8 Atü, and was significantly more efficient due to the change in the position of the fire box despite the constant heating surface. The current boiler system is the fourth.
Chains
The excavator was moved with the forward or forward chain, which - approx. 600 m long - was laid out with the help of a boat, and the side chain on the left ( port side ). The audio signals generated by a lift installed behind the operator's platform were used to estimate the distance covered when moving, each time it hit a vertical chain link (8 signals = ½ m). The excavator worked against the current, while it was held by anchors on the two chains. Signs to the side of the ship were used to signal the passing ships (white / red = passage, red = blocked, both sides red = no passage possible).
Control station
The large reel for operating the rudder blade was in the open air until 1948, when the current operator's platform was built. It was used to maneuver the excavator when it was being towed over long distances. The power transmission from the reel to the rudder worked via chain hoists.
Excavator cab
Small lateral handwheels are used to control the side and forward winds, the large wheel with the button operates the lift-up winch. The bucket ladder was lowered by operating a lever. An oval handle serves as a telegraph to the engine room to convey the operator's orders to the machinist (1 move = ahead, 2 = back, 3 = faster).
In recent years, the use of the excavator, which originally cost 48,000MM, has been controversial not only for economic reasons (excavator performance compared to more modern equipment, frequency of repairs), but also for ecological reasons. Smoking or steaming from the chimney and the exhaust pipe, it was described in the local press as a “rattling monster”. The energy consumption and the noise pollution, especially due to the clinking and scraping of the bucket chain, are no longer appropriate to today's technical standard. As a technical monument, the Minden excavator documents an interesting chapter in the history of technology as well as living and working conditions on board a dredger.
Data
- Year of construction: 1882
- Out of service: 1979
- Building yard: Gebr. Schultz machine factory, boiler forge and shipyard, Mainz
- Client: Royal Weser River Construction Administration for the Province of Hanover
- Overall length: 23.30 m
- Width overall: 6.18 m
- Draft: 0.94 m
- Height: 5.10 m
- Side height: 1.30 m
- Working draft: up to 6.50 m
- Dead weight: approx. 110 tons
- Drive: standing high-pressure cylinder steam engine, double-acting (until shutdown with coal firing)
- Power: 12 kW (16 HP) at 90 rpm
- Consumption: 50 kg / h coal
- Boiler: standing boiler system with cross boiler tubes; Current system (max.operating pressure 8 Atü) built in 1940
- Bunker: 45–48 ct. Coal = weekly consumption
- Buckets: until approx. 1932 gray cast, then steel cast, up to approx. 1923 there were 24 buckets (the chain of buckets was flatter at that time - storage level 4 m - that is, relatively low bridges - minimum height 4 m - could be passed, therefore the area of application could extend to Hanover via other waterways). Around 1923 the chain was extended by three buckets. Capacity per bucket: 71 liters
- Dredging capacity: before approx. 1923 approx. 25 - 30 t / hour, afterwards approx. 35 t / hour, after installing the sieve 75 t / hour. Annual output: between 1959 and 1979 with approx. 130-150 days of use, 20,000 to 45,000 m³ of fine dredging.
- Movement: The excavator was towed over long distances. Forward and side chains were laid out on site. The excavator could pull itself over shorter distances with the help of winches.
- Area of application: from Hameln to Stolzenau (approx. 100 kilometers of the Weser)
Web links
Coordinates: 51 ° 27 '26.8 " N , 6 ° 43' 53.2" E